Combined with the nature of enterprise property rights in China,and based on 2006-2012 seasonal financial data of the A shares listed companies in Shanghai and Shenzhen Stock Exchange, we study how monetary policy affects corporate debt financing(Bank loans; Credit) and the relationship between debt financing and investment efficiency. We obtain the following main conclusions: In the tight period of monetary policy, enterprise's debt financing will decline and investment efficiency will improve, the non-state-owned enterprises' debt financing declines more than the state-owned enterprises, credit financing is also less than the state-owned enterprises, and investment efficiency improve faster than the state-owned. This paper further studies the time lag effect of monetary policy on bank loans and the relationship between the institutional environment, bank loans and property rights.